The present invention relates to a method of producing petroleum and petroleum products from organic wastes and, in particular, a method for producing petroleum products by placing the organic waste in a permeable earth layer and subjecting the organic waste to high pressure and heat produced by the detonation of one or more explosive devices.
In nature, it is believed that gas and oil deposits are formed from organic materials which accumulate in layers in a given area. These organic deposits have not only decayed and decomposed to some degree but have slowly been buried as various forms of sedimentation occur. The progressive deepending of the layer of organic material plus geological upheavals cause the organic materials to be buried deep in the earth and subjected to enormous pressures as well as geothermal heat which eventually converts the organic materials to petroleum and petroleum related compounds. The present invention in effect duplicates this process in order to form petroleum compounds. However, the present invention performs this process in as short a time as several weeks while the natural process will normally occur over millions of years.
Various methods are known for producing methane gas from organic waste such as sewage and garbage. Specifically, in U.S. Pat. No. 4,057,401, filed Sept. 3, 1976 by Boblitz, an improved method of producing methane gas via bacterial action is described in which the production is facilitated by heating large quantities of organic waste material to promote the bacterial decomposition. However, in that patent, large quantities of complex equipment, including digester tanks, air tight enclosures surrounding the tanks, solar heaters, various conduits and various pumping apparatus, are required. By contrast, in the present invention, all that is required is a simple pump to pump the organic slurry into a permeable earth strata preferably having a temperature of about 100.degree. F. although a temperature of between 50.degree. and 150.degree. F. is also acceptable.
In another U.S. Pat. No. 3,640,846, filed Apr. 29, 1969, by Johnson, another method of producing methane from sewage solids is described in which the addition of coal substantially increases the production of methane by anaerobic digestion process. However, in that patent, there is no suggestion that production of methane by anaerobic digestion can be done in an earth strata or enhanced by the utilization of residual quantitites of oil in the earth strata in place of coal. Although such a result is not certain, it is believed that the residual oil contained in oil bearing geological formations will also promote the production of methane from an organic slurry comprised of sewage and pulverized garbage in the same manner that coal promotes the process described in the cited patent. In any event, the production of methane gas by anaerobic digestion comprises just one step in the present invention which includes a method of producing other petroleum components as well.
In another U.S. Pat. No. 3,606,999, filed Aug. 4, 1967, by Lawless, a method and apparatus for carrying out a chemical or physical process is disclosed in which it is necessary to apply high pressure to the various materials in order for the chemical reaction to occur. In particular, it provides for the oxidation of continuously flowing waste streams, such as sewage, by subjecting those waste streams to high pressure at suitable temperatures to induce various organic chemical reactions to produce organic compounds. In this patent, however, a deep well is drilled into the earth and filled with water. The head of water provides the necessary pressure. The materials to be reacted with each other are then pumped to the bottom of the well and subjected to the high pressures provided by the head of water. If heat is required, then artificial means must generally be provided to generate the heat.
By contrast, the present invention does not require the complex apparatus which the above patent requires. In addition, the above-cited patent does not provide for anaerobic digestion of any sort. Consequently, all the cited patent does is provide a high pressure zone into which various chemicals may be injected to induce chemical reactions which require high pressures.
In still another U.S. Pat. No. 3,864,208, filed Apr. 11, 1972, by Van Huisen, a process is disclosed for the destructive distillation of organic waste to produce gas and oil products. In this technique, an explosion is set off deep under the earth in a geological formation having a geothermal temperature of at least 300.degree. F. The explosion creates a cavity containing a large quantity of rubble having a high ambient temperature. Organic slurry is then pumped into the hot rubble. As the organic slurry percolates up through the hot rock, it is destructively distilled forming a layer of oil on top of the water containing the organic slurry.
By contrast, the present invention pumps the organic slurry into the earth prior to setting off the explosion not after. In addition, the cited patent nowhere suggests or discloses the use of a depleted or oil bearing geological layer as is preferred in the present invention, but rather requires an active geothermal geological layer. It will, of course, be appreciated that in such a hot geothermal layer, the anaerobic digestion of the present invention will not be possible because such digestion cannot occur above about 150.degree. F. Furthermore, the present invention utilizes an explosion to create heat and pressure which are immediately applied against the organic slurry to change the organic slurry into petroleum and gas products. Finally, unlike the above-cited patent, the method of the present invention is preferrably performed in an oil bearing geological layer containing otherwise non-recoverable petroleum. Thus, another advantage of the present invention over the prior art is that as a side product the heat created by the explosion of the present invention causes the otherwise unrecoverable oil deposits to be heated and made more viscous and thus more readily recoverable. Of course fields which have already been surveyed and found to be possible oil bearing areas are also acceptable geologically even though oil was not subsequently found. Use of such field and the existant geological data can greatly reduce the cost of practicing the present invention.
In this regard, U.S. Pat. No. 3,113,620, filed July 6, 1959, by Hemminger, discloses a particular method of generating heat in a depleted oil well to make oil therein which would otherwise be non-recoverable more viscous and, thus, recoverable. However, the present invention does not incorporate or require the elaborate process in that invention and indeed the present invention has as its primary objective the creation of oil rather than the recovery of previously non-recoverable oil.
Finally, it will be appreciated that in one alterative of the present invention, various elements or compounds such as iron or cobalt may be added to the organic slurry. When the explosive device is detonated these elements act as catalysts to promote the production of certain petroleum compounds over others. Thus, a certain amount of control over the type and quantity of various petroleum compounds is afforded.